uiz 7 MAT125 Name (Show all work to receive full credit. Round all answers to two decimal places.) 1) a) The average monthly car payment for a sample of 72 people who have a car loan is $392 with a standard deviation of $48. Construct a 90% confidence interval for the population mean monthly car payment for all people who have a car loan. Interpret your result. b) A claim is made that the population mean monthly car payment is $400. Using the results from part (a) of this problem, would this claim be valid or invalid